package com.tutucms.common.util;

import java.io.ByteArrayInputStream;
import java.io.InputStream;

/**
 * Title:
 * Description:
 *
 * @author WangXuDong
 * @version 1.0
 */
public class IOUtils extends org.apache.commons.io.IOUtils {

    /**
     * 将字符串转成InputStream
     * @param str
     * @return
     */
    public static InputStream toInputStream(String str){
        return new ByteArrayInputStream(str.getBytes());
    }


    /**
     * 将一个字符串中的汉字进行UTF8编码
     *
     * @param str
     *
     * @return
     */
    public static String toUtf8String(String str) {
        if (str == null || str.isEmpty()) {
            return str;
        }
        byte[] b;
        StringBuffer sb = new StringBuffer();
        for (int i = 0; i < str.length(); i++) {
            char c = str.charAt(i);
            if (c >= 0 && c <= 255) {
                sb.append(c);
                continue;
            }
            try {
                b = String.valueOf(c).getBytes("utf-8");
            } catch (Exception ex) {
                System.out.println(ex);
                b = new byte[0];
            }

            for (int j = 0; j < b.length; j++) {
                int k = b[j];
                if (k < 0) {
                    k += 256;
                }
                sb.append("%" + Integer.toHexString(k).toUpperCase());
            }
        }

        return sb.toString();
    }

    /**
     * 将UTF8字符串转换为汉字
     *
     * @param s %E4%BD%A0
     *
     * @return
     */
    public static String unescape(String s) {
        StringBuffer sbuf = new StringBuffer();
        int l = s.length();
        int ch = -1;
        int b, sumb = 0;
        for (int i = 0, more = -1; i < l; i++) {
            /* Get next byte b from URL segment s */
            switch (ch = s.charAt(i)) {
                case '%':
                    ch = s.charAt(++i);
                    int hb = (Character.isDigit((char) ch) ? ch - '0'
                                      : 10 + Character.toLowerCase((char) ch) - 'a') & 0xF;
                    ch = s.charAt(++i);
                    int lb = (Character.isDigit((char) ch) ? ch - '0'
                                      : 10 + Character.toLowerCase((char) ch) - 'a') & 0xF;
                    b = (hb << 4) | lb;
                    break;
                case '+':
                    b = ' ';
                    break;
                default:
                    b = ch;
            }
            /* Decode byte b as UTF-8, sumb collects incomplete chars */
            if ((b & 0xc0) == 0x80) { // 10xxxxxx (continuation byte)
                sumb = (sumb << 6) | (b & 0x3f); // Add 6 bits to sumb
                if (--more == 0) {
                    sbuf.append((char) sumb); // Add char to sbuf
                }
            } else if ((b & 0x80) == 0x00) { // 0xxxxxxx (yields 7 bits)
                sbuf.append((char) b); // Store in sbuf
            } else if ((b & 0xe0) == 0xc0) { // 110xxxxx (yields 5 bits)
                sumb = b & 0x1f;
                more = 1; // Expect 1 more byte
            } else if ((b & 0xf0) == 0xe0) { // 1110xxxx (yields 4 bits)
                sumb = b & 0x0f;
                more = 2; // Expect 2 more bytes
            } else if ((b & 0xf8) == 0xf0) { // 11110xxx (yields 3 bits)
                sumb = b & 0x07;
                more = 3; // Expect 3 more bytes
            } else if ((b & 0xfc) == 0xf8) { // 111110xx (yields 2 bits)
                sumb = b & 0x03;
                more = 4; // Expect 4 more bytes
            } else /* if ((b & 0xfe) == 0xfc) */ { // 1111110x (yields 1 bit)
                sumb = b & 0x01;
                more = 5; // Expect 5 more bytes
            }
			/* We don't test if the UTF-8 encoding is well-formed */
        }
        return sbuf.toString();
    }
}
